Atwood Water Heater Strange Problem

As stated, there might be a connection issue. #1 suspect in my consideration would be the connections to circuit board and then to the thermostats.

Thanks for the replies. Altitude has nothing to do with it. I live at 5200' and Iowa is only 1500'. I have camped at 9500' with no problems with the WH.

I will try Hank MI's suggestion.

Give a little tug on the wire going into the ignitor. On ours the wire had broke loose inside the ceramic. The high voltage spark would jump the gap but the millivolt signal coming back wouldn't. So it would ignite but not sense flame.

In your case the change in humidity could definitely be a factor. Also pull the spade connector off the control board and reinstall, other end of wire from ignitor.

or it could be altitude? What is the altitude at home? do you have a high alt. kit on your propane?

I would guess that the high humidity compromised the ceramic insulator allowing the high voltage spark to jump to ground someplace other than the spark gap at the burner. Also could be a weakness in the wire insulation leading to the igniter. Setting the spark gap to the smallest that will work may help.